If you're an overseas student applying to the University of Derby, you'll normally need to submit your application via UCAS, together with the necessary academic transcripts, a personal statement, maybe recommendation letters, and evidence of your English language skills. Additionally, you must fulfil certain English language criteria, which could include having an IELTS score of 6.5 with at least 5.5 in each part or having comparable credentials. 

IELTS: Generally, a score of 6.5 is needed, with at least 5.5 in each of the four sections (speaking, listening, writing, and reading). 
Options: Other comparable English language assessments, such the PTE Academic, TOEFL iBT, or Cambridge English credentials, might be accepted by the university.